Label-applying apparatus for applying thermoplastic labels

Abstract

In a label-applying machine for applying labels adapted to be rendered adhesive by an application of heat, a vacuum picker for removing the labels one at a time from the magazine and moving them to a transfer position, a vacuum gripper finger at the transfer position for taking the labels from the picker and moving them to a position for application to containers supported for movement along a predetermined path, said gripper fingers being heated to render the labels tacky during movement from the transfer position to the containers for spotting the labels on the containers, and wipers situated along the path of travel of the containers beyond the place of spotting of the labels for pressing the labels against the sides of the containers, and means for heating the wipers to cause the labels to be adhesively attached to the containers.

I claim: 
     
       1. The method of applying thermoplastic labels to containers comprising vacuum picking dry thermoplastic labels one at a time from a stack of dry labels, transferring the dry labels to a place of application to a container, while making the transfer heating a portion of the label to render said portion tacky, pressing the tacky portion of the label against the container at the place of application and then while moving the container along a predetermined path away from said place of application heating the entire area of the label to make it adhesive and pressing it against the container. 
     
     
       2. The method of attaching labels which may be rendered adhesive to the sides of containers traveling along a predetermined path at a predetermined rate, comprising rendering a portion of the label tacky and at a predetermined place along said path pressing the tacky portion of the label to the sides of the container causing it to become attached thereto and thereafter while the container continues to travel a predetermined distance along said path pressing the entire area of the label into engagement with the side of the container and simultaneously rendering the entire area of the label uniformly adhesive to obtain uniform adhesion of the label to the container. 
     
     
       3. A method according to claim 2, comprising rendering said portion of the label tacky by subjecting said portion of the label to a temperature of 250°-300° F. 
     
     
       4. A method according to claim 2, comprising rendering the entire area of the label adhesive by subjecting the entire area of the label to a temperature of 300°-350° F. 
     
     
       5. The method of applying thermoplastic labels to containers comprising vacuum picking dry labels one at a time from a stack of dry labels, presenting the vacuum picked labels to a place of transfer, vacuum gripping the label at the place of transfer and moving it to a place of application, heating a portion of the label as it is moved from the place of gripping to the place of application, spotting the tacky portion of the label at the place of label application to the container, moving the container with the spotted label thereon along a predetermined path away from said place of label spotting, and while moving along said path rendering the entire area of the label adhesive and pressing its entire area against the container. 
     
     
       6. The method of applying thermoplastic labels to containers comprising reciprocably moving a vacuum picking element between a label holding magazine at a place of transfer to pick dry thermoplastic labels one at a time from the magazine and present them to the place of transfer, reciprocably moving a vacuum gripper finger from the place of transfer to a place of label application for taking the vacuum picked labels from the picker element and applying them to containers at the place of application, heating a portion of the label as it is taken by the gripper element and moved from said transfer position to said position of application to cause the label to become adhesively spotted to the container at the place of label application and thereafter moving the container away from the place of application along a predetermined path and while so moving it compressively wiping the entire surface of the label against the container and simultaneously heating the entire area of the label to render it adhesive.  pg,16 
     
     
       7. In a labeling machine, label applying instrumentalities and a support for supporting and moving containers along a predetermined path relative to the label-applying instrumentalities, said instrumentalities comprising label applying means and label wiping means arranged along said path such that the containers are presented successively thereto, said label applying means comprising a magazine for holding a stack of labels adapted to be rendered adhesive by application of heat, a vacuum picker movable from the magazine to a transfer position and back for removing labels one at a time from the magazine and moving them to the transfer position and a vacuum gripper finger comprising a yieldable pad having a label pressing surface containing at its ends vacuum orifices, said vacuum gripper finger being movable from the transfer position to the support and back again to take labels from the vacuum picker and press them against the side of the container on the support, heating means on the gripper finger pad confined to a relatively small area of the pressing surface substantially midway between the orifices for rendering a correspondingly small area of the label intermediate its ends tacky so that the pressure applied by the pressing surface of the pad adheres the tacky area only of the label to the side of the container leaving the non-tacky portions unattached, and said wiping means comprising a wiping pad movable to and from the path of movement of the container and along the path of movement having a label pressing surface for pressing the entire area of the label against the side after it has been initially adhered to the side by the gripper finger, said wiping pad being arranged to be retained in engagement with the sides of the container for a predetermined length of time while traveling along said path and heating means coextensive with the label pressing surface of the wiping pad for rendering the entire area of the label adhesive while in compressive engagement with the container. 
     
     
       8. Apparatus according to claim 7, wherein there is means for moving the wiping means to and from the path of movement of the container and the heating means for the wiping pad is imbedded therein. 
     
     
       9. Apparatus according to claim 7, wherein the wiping pad has a concave face for wrapping the label about the sidewalls of the containers. 
     
     
       10. Apparatus according to claim 7, wherein articulated jaws supported for angular movement about a spaced parallel axis parallel to the surface of the container support the wiping pad for wrapping about the sides of the containers. 
     
     
       11. Apparatus according to claim 7, wherein the wiper pad has a concave face and there is a thin sheet of heat conductive metal attached to and co-extensive with said concave face of the wiper pad. 
     
     
       12. Apparatus according to claim 7, wherein the wiping means is reciprocably movable along the path of movement of the containers. 
     
     
       13. Apparatus according to claim 7, wherein there are several wipers situated along the path of movement of the containers such that each container will be subjected to as many wiping operations as there are wipers.